Rashi on Genesis 18:13/רש"י על בראשית י״ח:י״ג

1האף אמנם means SHALL I REALLY BEAR?

2ואני זקנתי I BEING OLD — Scripture (God) in relating her words to her husband alters them for the sake of peace, for she had said (v. 12) “my lord is old” (Genesis Rabbah 48:18).